An empirical study of control flow graphs for unit testing

Abstract

This paper conducts an empirical study of a Control Flow Graphs (CFG) visualizer from which various test coverages can be exercised directly. First, we demonstrate how control structures are extracted from bytecode and compound conditions are decomposed into simple multi-level conditions in Java bytecode. Then, we visualize the decomposed compound conditions in CFG. The layout of a CFG is calculated by extending a force-directed drawing algorithm. Each control node of CFG represents a simple condition. The empirical study shows that (1) the tool successfully decomposes a compound condition into simple multi-level conditions and (2) the extended force-based layout algorithm produces the best layout for visualizing CFG.